Factors influencing primary care physicians' prescribing behavior of anticoagulant therapy for the management of patients with non-valvular atrial fibrillation in Singapore: a qualitative research study.

Background: Oral anticoagulant therapy use in patients with atrial fibrillation (AF) remains suboptimal in Singapore, despite the availability of both warfarin and non-vitamin K antagonist oral anticoagulants (NOACs). Primary care physicians' (PCP) decision-making to initiate and select appropriate anticoagulant medication is pivotal in reducing complications among patients with AF. This study explored the factors influencing PCPs' decision-making in anticoagulant initiation and anticoagulant switch for patients with non-valvular AF.

In-vivo lung biomechanical modeling for effective tumor motion tracking in external beam radiation therapy.

Lung cancer is the most common cause of cancer-related death in both men and women. Radiation therapy is widely used for lung cancer treatment; however, respiratory motion presents challenges that can compromise the accuracy and/or effectiveness of radiation treatment. Respiratory motion compensation using biomechanical modeling is a common approach used to address this challenge.

Deep cerebral microbleeds are associated with poor cholinesterase inhibitor treatment response in people with Alzheimer disease.

Objectives: Cholinesterase inhibitors (ChEIs) are the most effective treatment for Alzheimer disease (AD), but the response to treatment varies. Vascular lesions are associated with the pathogenesis of AD, and cerebral microbleeds (CMBs) are an indicator of hemorrhagic vascular pathology, which can be detected through susceptibility-weighted magnetic resonance imaging (SWMRI). This study investigated the association between CMBs and ChEI treatment response in patients with AD.

Confirmatory Study of Time-Dependent Computed Tomographic Perfusion Thresholds for Use in Acute Ischemic Stroke.

Background and Purpose- Computed tomographic perfusion (CTP) thresholds associated with follow-up brain infarction may differ by time from symptom onset to imaging and reperfusion. We confirm CTP thresholds over time to imaging and reperfusion in patients with acute ischemic stroke from the HERMES collaboration (Highly Effective Reperfusion Evaluated in Multiple Endovascular Stroke Trials) data. Methods- Patients with occlusion on CT angiography were acutely imaged with CTP.

Defining CT Perfusion Thresholds for Infarction in the Golden Hour and With Ultra-Early Reperfusion.

In this brief report, computed tomography perfusion (CTP) thresholds predicting follow-up infarction in patients presenting 20 to 23 seconds and cerebral blood flow <5 to 7 ml/min-1/(100 g)-1 or relative cerebral blood flow <0.14 to 0.20 optimally predicted the final infarct.

[F]-DCFPyL Positron Emission Tomography/Magnetic Resonance Imaging for Localization of Dominant Intraprostatic Foci: First Experience.

An ongoing prospective study is acquiring preoperative imaging data for men with prostate cancer (PCa) using the molecular imaging agent [F]-DCFPyL targeted against prostate-specific membrane antigen (PSMA). To date, six men (of a planned accrual of 24) with clinically localized, biopsy-proven PCa have undergone preoperative [F]-DCFPyL positron emission tomography (PET) imaging and multiparametric magnetic resonance imaging acquired using a hybrid PET/MRI system. Lesions identified by [F]-DCFPyL uptake on PET/MRI were characterized in terms of maximum standardized uptake value (SUV) and volume using a boundary threshold of 40% SUV.

Time-Dependent Computed Tomographic Perfusion Thresholds for Patients With Acute Ischemic Stroke.

Background And Purpose: Among patients with acute ischemic stroke, we determine computed tomographic perfusion (CTP) thresholds associated with follow-up infarction at different stroke onset-to-CTP and CTP-to-reperfusion times.

Methods: Acute ischemic stroke patients with occlusion on computed tomographic angiography were acutely imaged with CTP. Noncontrast computed tomography and magnectic resonance diffusion-weighted imaging between 24 and 48 hours were used to delineate follow-up infarction.

Temporal changes in blood-brain barrier permeability and cerebral perfusion in lacunar/subcortical ischemic stroke.

Background: Cerebral microvascular abnormality is frequently associated with lacunar and subcortical ischemic lesions. We performed acute and follow-up CT perfusion scans over the first 3 months after ischemic stroke to investigate disturbances of the blood-brain barrier (BBB) and cerebral perfusion in patients with lacunar/subcortical lesions compared to those with cortical lesions alone.

Methods: Thirty-one patients with lacunar/subcortical infarct (n = 14) or with cortical large vessel infarct (n = 17) were recruited and underwent a CT perfusion study at admission, 24 h, 7 days and 3 months after stroke using a two-phase imaging protocol.

CT perfusion cerebral blood volume does not always predict infarct core in acute ischemic stroke.

We investigated the practical clinical utility of the CT perfusion (CTP) cerebral blood volume (CBV) parameter for differentiating salvageable from non-salvageable tissue in acute ischemic stroke (AIS). Fifty-five patients with AIS were imaged within 6 h from onset using CTP. Admission CBV defect (CBVD) volume was outlined using previously established gray and white matter CBV thresholds for infarct core.

Acute Multi-modal Neuroimaging in a Porcine Model of Endothelin-1-Induced Cerebral Ischemia: Defining the Acute Infarct Core.

In a porcine ischemic stroke model, we sought to compare the acute predicted infarct core volume (PIV) defined by CT perfusion (CTP)-hemodynamic parameters and MR-diffusion-weighted imaging (MR-DWI)/apparent diffusion coefficient (ADC), with the true infarct core volume (TIV) as defined by histology. Ten Duroc-cross pigs had a CTP scan prior to injection of endothelin-1 (ET-1) into the left striatum. CTP scans were used to monitor ischemic progression.

Hemodynamic effects of combined focal cerebral ischemia and amyloid protein toxicity in a rat model: a functional CT study.

Background/objective: Clinical evidence indicates that cerebral ischemia (CI) and a pathological factor of Alzheimer's disease, the β-amyloid (Aβ) protein, can increase the rate of cognitive impairment in the ageing population. Using the CT Perfusion (CTP) functional imaging, we sought to investigate the interaction between CI and the Aβ protein on cerebral hemodynamics.

Methods: A previously established rat model of CI and Aβ was used for the CTP study.

Stress hypoperfusion and tissue injury in hypertrophic cardiomyopathy: spatial characterization using high-resolution 3-tesla magnetic resonance imaging.

Background: Ischemia and tissue injury are common in patients with hypertrophic cardiomyopathy. Cardiovascular magnetic resonance imaging offers combined evaluations of each phenomenon at sufficiently high resolution to examine transmural spatial distribution. In this prospective cohort study, we examine the spatial distribution of stress perfusion abnormalities and tissue injury in patients with hypertrophic cardiomyopathy.

The evolution of the cerebral blood volume abnormality in patients with ischemic stroke: a CT perfusion study.

Background: Accurate identification of the acute infarct core abnormality is important for guiding acute stroke treatment. Abnormality volumes from diffusion-weighted MRI (DWI) and CT perfusion (CTP)-cerebral blood volume (CBV) are highly correlated. DWI lesions have been shown to be reversible at 24 h.

A novel dextran-oleate-cRGDfK conjugate for self-assembly of nanodrug.

Unlabelled: We report a novel synthetic biocompatible material: a conjugate with a fatty acid-substituted dextran decorated with cRGDfK peptide, which was used as a stable coating material instead of the conventional poly(ethylene glycol) for nanodrug preparation. This novel dextran-oleate-cRGDfK conjugate (DO-cRGDfk) could self-assemble into a micellar structure in aqueous solution, and was used as a surfactant to formulate nanodrug with poly(d,l-lactic-co-glycolic) acid as matrix to encapsulate paclitaxel with high drug-loading efficiency. The conjugate allowed the fabrication of nanodrug with a targeting moiety on its surface in a simple and robust step.

The Intracerebral Haemorrhage Acutely Decreasing Arterial Pressure Trial: ICH ADAPT.

The majority of intracerebral haemorrhage patients present with markedly elevated blood pressure immediately after symptom onset. Management of blood pressure in the first 24 h is extremely controversial and lends itself to two competing rationales. There is some evidence that early treatment may improve outcome, potentially by reducing the rate of haematoma expansion.

Predicting postoperative FEV1 using spiral computed tomography.

Rationale And Objectives: Lung resection for primary bronchogenic carcinoma in the setting of chronic obstructive pulmonary disease often requires a detailed assessment of lung function to avoid perioperative complications and long-term disability. The aim of this study was to test the hypothesis that a novel technique of spiral computed tomographic (CT) subtraction imaging provides accuracy equal to the current standard of radioisotope perfusion scintigraphy in predicting postoperative lung function.

Methods And Materials: Preoperative lung function, radioisotope perfusion scintigraphy, spiral CT subtraction imaging, and assessment of postoperative lung function were performed in 25 patients with surgically resectable primary bronchogenic carcinoma.

The effects of botulinum toxin type A on muscle blood perfusion and metabolism.

Background: Botulinum toxin type A is approved by the U.S. Food and Drug Administration for the treatment of facial rhytides.

The effects of masseter muscle paralysis on facial bone growth.

Background: Understanding the effects of muscle function on facial bone growth may help us treat children with facial anomalies. Facial bone growth is known to be a result of both genetic and epigenetic influences. One of the main epigenetic factors controlling growth is thought to be muscle action.

Functional CT for quantifying tumor perfusion in antiangiogenic therapy in a rat model.

Purpose: To determine the histologic basis of perfusion parameters measured at functional computed tomography (CT) and to examine the relationship between changes in perfusion and changes in histologic parameters after antiangiogenic therapy in a rat model.

Materials And Methods: This study had institutional animal care and use committee approval. Among 20 Fischer rats with implanted FN13762 tumors in the liver, 10 were treated with SU5416, a tyrosine kinase inhibitor of vascular endothelial growth factor receptor, and 10 were treated with the diluent only as control rats.

Assessment of the tumor microenvironment in cervix cancer using dynamic contrast enhanced CT, interstitial fluid pressure and oxygen measurements.

Purpose: Interstitial fluid pressure (IFP) and oxygen (pO(2)) measurements are prognostic factors in cervical cancer. The purpose of this study was to determine the relationship between IFP and oxygenation and parameters derived from dynamic contrast-enhanced computed tomography (DCE-CT).

Methods And Materials: Dynamic contrast-enhanced computed tomography was performed in 32 patients with cervical cancer before radiation therapy.

A subtle change in p38 MAPK activity is sufficient to suppress in vivo tumorigenesis.

Emerging evidence supports a role for p38 MAPK in negative regulation of tumorigenesis. Here we show that a subtle activation of p38 MAPK is sufficient to suppress tumorigenesis as measured by the ability to form tumors when MKK6-inducible cells were explanted into nude mice. On the other hand, this activation of p38 MAPK did not necessarily cause an immediate inhibition of cell growth in vitro as measured by standard MTS assay.

The effect of varying user-selected input parameters on quantitative values in CT perfusion maps.

Rationale And Objectives: Deconvolution-based software can be used to calculate quantitative maps of cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) from first-pass computed tomography perfusion (CTP) datasets. The application of this software requires the user to select multiple input variables. The purpose of this study was to investigate the degree to which both major and minor variations of these user-defined inputs would affect the final quantitative values of CBF, CBV, and MTT.